The present invention relates to an electronic lock, and more particularly to an electronic anti-theft lock having an electromagnetic valve that is excited to extend a rod to stop a locking bolt from moving inward to open the lock only when a key with incorrect IC code is detected by an internal control circuit of the lock, and the extended rod can be mechanically depressed again by a restoring plate, making the lock simple, reliable, and practical for use.
People use locks and keys to protect their life and properties against infringements by others. A conventional lock is usually mechanically opened with a key. For an experienced thief, such conventional mechanical lock can be opened within only one or two minutes. Therefore, the conventional lock actually forms a potential threat to people""s life and properties. There are various types of electronic locks developed and available in the market, such as IC cards, magnetic cards, combination locks, wireless remote-control locks, and the like. Most of these electronic locks include a locking mechanism having an internal electric-powered mechanism, such as an electromagnet or an electric motor, which enters into and keeps in an unlockable state once the lock is closed. To open an electronic lock, a key corresponding to the electronic lock must be inserted. When an internal microcomputer of the electronic lock detects from the inserted key a correct IC code, it sends out a command to release the electric-powered mechanism from the unlockable state and energizes the same to open the lock.
It is unquestionable the electronic lock controlled with an IC code provides very good anti-theft function. However, there are still some problems with the actual use of such electronic lock. A major one of these problems is the locking mechanism of the conventional electronic lock enters into and keeps in the unlockable state for a prolonged time once the lock is closed. In the event any of the circuits, batteries or electric-powered mechanism inside the lock is disordered, an embarrassing condition of an unlockable electronic lock would occur. A common practice to overcome this problem is to add a preparatory lock to the electronic lock. When a part of the circuits of the electronic lock becomes failed, for example, due to exhausted batteries or problems with the electronic circuits thereof, a user may use a key to mechanically open the electronic lock via the preparatory lock. A problem with the preparatory lock is it can be unlocked with general lock-opening tools even if the electronic lock is in good condition. Thus, the preparatory lock forms another potential threat to the user and largely reduces the anti-theft function of the electronic lock. This is why the conventional electronic locks are applied to only limited places.
It is therefore tried by the inventor to develop an electronic anti-theft lock that enters into an unlockable state only when a chip-contained key having an incorrect IC code is detected, and the unlockable state can be released via a mechanically movable restoring plate inside the lock, making the lock simple, reliable, and practical for use.
A primary object of the present invention is to provide an electronic anti-theft lock that enters into an unlockable state only when a chip-contained key having an incorrect IC code is detected, and the unlockable state can be released via a mechanically movable restoring plate inside the lock.
To achieve the above and other objects, the electronic anti-theft lock of the present invention mainly internally includes an electromagnetic valve having a vertically movable rod; a locating mechanism that includes a turning plate adapted to shift the whole mechanism inward or outward in multiple steps, a restoring plate adapted to mechanically depress the rod of the electromagnetic valve at an upward extended position, and a stopper adapted to contact with the extended rod of the electromagnetic valve to stop the locating mechanism from moving inward further; and a control circuit adapted to detect a correct IC code of an inserted chip-contained key, and to excite the electromagnetic valve to extend the rod to stop a locking bolt of the locating mechanism from moving inward to open the lock only when an incorrect IC code is detected. And the unlockable state can be released by depressing the extended rod of the electromagnetic valve with the mechanically movable restoring plate, making the lock simple, reliable, and practical for use.